SITE INFORMATION AND CORRESPONDENCE

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Mr. Mike Desso • -5- • 31 August 2011 migration has occurred. Continued investigation work farther northwest and west will complete the A Zone characterization. Also, additional investigation work in this area in the C Zone will help to define the migration pathways for TCE and its degradation products in the C Zone. The following work will help Nestle complete the investigations in both zones. 1) Prior to conducting any additional drilling, Nestle must complete additional geologic cross sections using data that are already available. The cross-sections should be prepared along the following transects: a) From the northwest end of cross-section A'-A through well nest M-45 to City well MW-5. b) From the east end of cross-section B'-B beneath US Highway 99 to well nest M-16. c) From the west end of cross-section B'-B through Ripon USD supply well RPS-1 and the M-27 well nest to City well MW-10. d) From the west end of cross-section C'-C through the M-13 well nest, the M-28 well nest, City well MW-3, and the M-29 well nest to City well MW-10. e) From the former facility through CPT-4 through the M-6 well nest (including M-49A) to the M-18 well nest. f) From the southeast end of cross-section A'-A through the M-6 well nest (including M-49A) and the west end of cross-section C'-C to the west end of cross-section B'-B. The geologic cross-section report must make recommendations for installation of additional _monitoring_wells and-soil borings along these transects to complete the characterization of the extent to which COCs have migrated from the former facility in the A and C Zones. 2) After Central Valley Water Board staff has reviewed the cross-section report required in Item 1, Nestle should prepare and submit a work plan to implement the report recommendations and staff comments. In addition to the recommendations and comments, the proposed work should include the following: a) An evaluation of the likelihood that existing guard wells will detect CDCs that have migrated beneath US Highway 99 before they impact City water supply well MW-5. b) One or more monitoring wells screened within sandy units of the A Zone at nest M-13. c) A schedule for discussions between Nestle and the City regarding recent detections of COCs in guard well nest M-28 and City water supply well MW-3, and MW-3 pumping rate management. d) An evaluation to show whether or not the existing guard wells for City water supply well MW-10 are placed in the sandy units from which it extracts water. e) A summary of the discussions between Nestle and the Ripon USD, and between Nestle and the Ripon Christian School management regarding decommissioning of school supply wells and hookup to the City water supply systems. 3) Nestle must resume quarterly monitoring and sampling of well M-1 3A beginning with the fourth quarter 2011 event. 4) Nestle must include the locations of all referenced wells, including City water supply wells, on future well location figures, such as Figure 2 of the 2010 Annual Report.